1. Technical Field
The present invention relates to a polarization conversion device and a projector system.
2. Related Art
According to a related art, a polarization conversion device which is used for a projector and includes a polarizer arranged in a position preceding a projection lens of the projector and a ½ wave plate arranged in a position subsequent to the projection lens is known (see, for example, JP-A-2005-43656). With the related-art polarization conversion device, light emitted from the projector can be projected onto a screen as a projection image formed by light in a uniform polarization direction.
Such a projection image formed by light in a uniform polarization direction can be used, for example, to project a stereoscopic projection image.
However, the related-art polarization conversion device has a problem that optical elements involved in polarization (the polarizer and the ½ wave plate in the related-art polarization conversion element) are distorted or are deteriorated in a short period. If the optical elements are distorted, the optic axis is shifted, causing the occurrence of in-plane unevenness of phase difference and hence the occurrence of in-plane unevenness of luminous intensity and in-plane unevenness of color in the projection image. Also, if the optical elements are deteriorated, the polarization conversion device cannot be used.